Turn indicator



L. B. SERRY,

TURN INDICATGR.

APPLICATION FILED MAY 21.1920.-

,433., 162. Patented Oat. 2i, 1922.

WM5' yw, fi@ KQSWI-W l Patented Oct. 24, 1922.

LAWRNCE B. SPERRY, OF GARDEN CITI' IEW YORK, ASSIGNOR T0 THE SPERRY GYROSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

Application 'tiled May 21,

T o all vwhom it may-coo'icern.:

Be it known that I, LA. ENCE B. SrsnRY, a citizen of the United lStates of America, residing at (.irardenv City, Long Island` in the countv of Nassau and State of 'New York, have invented certain new and useful Improvements in Turn Indicators, of which the following is a specification.

This invention relates to gyroscoplc turn indicators for aircraft or other dirigible vehicle and more particularly to the improvemenfts in the apparatus shown anddescribed in the copending application of Elmer Sperry for turn indicators, Serial ho. 353,789, tiled January 20, 1920.

According to this invention a small gyroscope mounted for precession about a horizontal axis upon turning of the craft upon which it is mounted is made use of to intelicate turning by means of a suitable 1ndicator. Such an instrument has been found to be ver sensitive but in its original form many de ects appeared, the purpose of this invention being to overcome the defects in the original instrument.

A further object of the invention 1s-to provide means for use in conjunction with1 the turn indicator proper for showing the banking angle of the airplane.

Referring to the drawings in Whichare now considered preferred forms of the invention are shown:

Fig. 1 is a horizontal section of one forni of turn and banking indicator.

Fig. i2 is a vertical section of the same.

Fig. 3 is a detail in section ofthe controlling valve for exhausting the air lin the casing.

Fig. 4 is a front elevation of a modified form of indicator.

l ig. 5 is a vertical section of the same.

Fig. 6 is a sectional detail of the regulating valve.

y The turn indicator comprises preferably a closedv casing 1 in which is pivotally mounted a frame 2 supported on horizontal pivots 3 and 4. Said pivots are preferably inpractice placed fore and aft of theairplane, is journalled in suitable anti-friction bearings 6 and 7. Said rotor is preferably brult up of a plurality of parts comprising a cenral flat'disc Sshrunk or otherwise secured to the shaft 9 and a pair of heavy rings 10 In said frame -the rotor proper TURN INDICATOR.

1920. Serial FIO. 383,106.

lubricated by oil wicks 24 and 25 extending throughout the length of the frame as shown in Fig. 1. Suitable passages 26 and 27 may leadfrom said Wicks to the frame bearing 3 and other passages 76, 77 may lead from said wicks to the rotor bearings. By such construction the bearings' remain oiled indenitely and wateris excluded therefrom.

As shown in Fig. 1 the air is introduced into the casing through la hollow pivot 14 communicating with the exterior of the casing at 15. Said pivot may be made in the form of a separate closure 16 threaded in an aperture in the end ofthe casing` and having a tube 17 constituting pivot 14 secured to, or integral with, the same. A screen 18 may also be secured to the outer end of the casing for preventing foreign matter from being carried into the casing with the air.

At the forward endof the frame 2 is shown secured a gear 28 which meshes with a pinion 29 on the shaft 30. A light paddle or blade 31 is shown as' mounted on Said. shaft for the purpose of damping theoscillations of the gyroscope. Also mounted Within said frame 1 is a Simple pendulum 32 or other pendulous device. Said pendulum is shown as having secured thereto a gear 33 meshing with pinion 34. also carrying a blade or paddle 35 for damping purposes. Also secured to said gear and pendulum arev a pair of normally horizontal indicators 3G and 37 secured to the outer ends of oppositely extending arms 38'and 39. Said indicators are readable upon a stationary dial or index 40 which has marked thereon reference indications 41 and 42 to simulate the horizon line, in other wor'ds,"to simulate the line the aviator normally employs as indicating horizontality. The gyroscope also has secured to the frame 2 thereof an arm 44 bearing a normally vertical indicator 45. Said indicator is preferabl readable upon the same dial 40. Said. dia is preferably marked in such a manner: as to indicate roughly the outline of' the radiator or hood of the airplane since it is the cap on the radiator. which is usually 0bserved by aviators-With reference to a distant object to ascertain Whether the airplane is turning or not. A number of graduations 47 may be provided to indicate the rate of turning of the airplane.

Suitable stops 50 are, of course, provided Within the casing for preventing the gyroscope from turning too far or from turningl over. Said stops are shown as pieces of rubber tubing mounted on .transverse lead and adapted to cooperate With the bearing frame 2 -of the gyroscope. Also it is important that a vcentralizing means be einployed for normally holding the gyroscope i 1n the `yertical or other predetermined position and only permitting turning or precession thereof upon turnlng of the aircraft. Spring or springs as ordinarily secured to 'the gyroscope are unsuited for this purpose owing to the fact that if made Weak enough to permit suiiicient sensitiveness of tlie gyroscope to indicate a slight turnwhen a sharp turn is taken the gyroscope Will immediately recess over and strike the stop from whence it will start oscillating back and forth and become useless. On the other hand if the spring is made stiffl enough to prevent its being too sensitive under the conditions stated it will not be sensitive to slight turns of the aircraft and Will not fulfill its coinyplete function.

`For the purpose of overcoming these dif'licultiesl have shown one or more sensitive spiral springs 51 and 52 secured between opposite points 53 and 54 on frame 2 and points on the casing. The springs are preferably vin line with each other and under.

little tension when the gyroscope kis in the. normal position. It will readily be seen that With this arrangement very little force will oppose the initial procession 'of the gyroscope so that 'it will be very-sensitive to slight turns of the airplane. On the other hand the force exerted by the springs will rapidly increase with vthe angle of preces-v sion ofthe gyroscope so that n ot only will the gyroscope be prevented from striking the stops but also the angle that the gyroscope is able to turn against the springs Willv furnish a ready indication of the rate of turning of the aircraft in a similar manner that a springbalance shows the acceleration of gravity upon a mass hung thereon, since gyroscopic effort is directly proportional to the rate of vturning of its precession axis.

Preferably means are provided for adjusting the tension of one or both springs 5l l or 52. For this purpose at the outer end of in turn is *secured to the rotatable rod 58 mounted in the casing.v Said rod has fixed thereto at its forward end a combined thumb. piece yand indicator 59 readable on scale 60 so that the' tension of the spring may be readily adjusted to any desired extent. A

second thumb' piece and indicator 61 is mounted preferably at thelower part of the `the spring 52 is secureda thread 57 Which casing, being readable upon the scale 62.,

Said thumb piece is mounted '.on a shaft 63 to which is secured a rotary valve 64 for .closing and opening the outlet passage 65 from the casing. Said outlet passage is preferably connected to a low point on the casing l, as showmso that anycondensed vapor may be readily Withdrawn therefrom. The valve 64 is journalled in `the Valve fitting 66, said tting being providedwith an extension 67 to which a flexible hose may be secured." It will be understood that in operation, air is exhausted from the cas' ing through the openino` 65 and fitting 66 by coupling any suitabe type of exhaust pump thereto, such as a Venturi tube mounted on the airplane, as illustrated in.

the aforesaid copending application of` pressure up to the desired amount for maintaining the proper speed of the gyioscope.v Bythis means the speed is maintained comparatively constant irrespective of the Variationsr in the rate of exhausting due to cliangesin the speed of .the airplane or other cause.

Vhile the principal features of the turn indicator shown in Fig. 5 are the same as already described, aimodiied form of damp ing means for the pendulum 32 is illustrated. In this form of the invention the pendulum illustrated is suspended Within the closed casing 74 filled with liquid as a damping medium. At the same time the fan for damping `the gyroscope, as Well as the fan on the' pendulum, isl also omitted. The damping action of the bearings and the centralizing.springs are depended upon in' this instance addition only shown. Also,1 .instead of bringing i-i'n the' air th'roughrthe-liollow trunnion of thel to damp the gyroscope. -In vone centralizing .spring 751 is' A' tiebe communicating with combination with a `gyroscope mounted for procession about an axis, of yielding centralizing means therefor which increasingly opposes precession of the gyro as it becomes further displaced from its normal position, and means for adjusting said yieldingr means. l

Q. A. flying indicator for aircraft comprising a reference member, a movable normalty horizontal member symbolizing 'the horizon adjacent thereto, a second normally vertical indicator, a pendulous device connected tothe first mentioned member and a g roscope'mounted for precession on turning of the aircraft connected with lsaid vertical indicator.

3. in an air driven gyroscope, the combination with the rotor, of a closed casing, a the interior thereof and connected to the same at a low point on-the casing to draw air and condensed vapor therefrom, and an intake nozzle adjacent the rotor. I

a. In a banking indicator, the combination with a pendulous device, an indicator connccted thereto a dial on which said indicator is readable, and a. gyroscopic turn indicator i readable on the same dial.

" hicle's, a gyroscope mounted for procession about/' an airis at an angle to thevertical;

'ing a gyroscope,

5. A gyroscopic turn indicator comprismeans for mountingthe saine for procession zontal axis, said gyroscope being fixed about the vertical axis, yielding ccntralizing means connected to the gyrr :pe about said horizontal axis Whic opl orecession of the gyroscope about said axis with increasing force as said gyroscope becomes displaced from its normal 'position and means for damping the oscillation of'said gyroscope about said axis.

6. A turn indicator comprising a gyroscope, means for mounting the same for precession about'an axis at an angle to the vertical, said, gyroscope being fixed aboutA the .vert-ical airis, and means comprising a spring under a slight initial stress when the gyroscope is in its normal position for offering very' little `force. to small precessional movements of the gyroswcope but Afor opposing further prcession with greatern force whereby the extent'zof procession ofthe gyroscope furnishes ani'ndicatin oftherate of turn. .7; in `a turn indicator for dirigible ve:

in response to turning of the vehicle in azi- .pendulous device, an vindicator about a normally Dori-- rsaid yielding means of springs connected with said gyroscope in line with each other each of which opposesprecession of said gyroscope about said axis in each direction.

8. n a turn indicator for aircraft, a frame, a support, pivots connecting said frame and said support for permitting movement of said frame about an axis at an angle to the vertical, a rotor mounted in said frame for rotation about another axis, a spring connected to said frame adjacent one of said pivots for opposing movement of muth, and a plurality lsaid frame in either of opposite directions about said axis and means for adjusting the tension of said spring at will.

9, In a flying indicator fdr aircraft, means including a reference member for indicating when the aircraft turns about an axis, and means including,r the af resaid` reference member for indicating when the aircraft turns about another ai'is.

l0. In a flying indicator for aircraft, a connected thereto, a reference member-in -connection Withwhich said indicator is readable, a second indicator readable in connection With. said reference member, a gyroscope mounted for procession upon turning of the aircraft, and connecting means between said gyroscope and said second indicator.

1l. in a turn indicator` for aircraft, a frame, a support, pivots connecting said frame and said support for permitting movement. of said frame about an axis, at an angle to the vertical, a rotor mounted in said frame for rotation about another axis, and a spring connected to said framev adjacent one of said pivots for opposing movement of said frame in either of vopposite directions about said axis.

'12. In a turn indicator for dirigible vehicles, a casing, ay gyroscope mounted for precession Within said casing about an airis at an angle to the vertical, a passage for a current fair through one end of said casing, and means for causing said current of air to rotate said gyroscope.

13. ln a turn indicator for dirigible vehicles, a gyroscope mounted for precession about an axis at an angle to the vertical, yielding means for opposing said precession, and means comprising airotatable member for altering at will the resistance offered by to said precession.

11i, In a turn indicator for aircraft, a casing, a gyroscope mounted in said casingrl for precession about an axis, a tube connected to' said 'casing to conduct air therefrom, a passage for the ent-rance of air into said casing, means for directing)r the air to drive said A gyroscope as the air is drawn through the casing, a valve in said tube and means for adjusting said Valve at will to vary the' speed of rotation of the gyroscope.

l5, in a turn indicator for aircraft` a casics ing, a gyroscope mounted in said casing for precession about an axis, a tube connected to said casing to conduct air therefrom, a passage for the entrance of air into said oasing, means for directing the air to drive said gyroscope as the air is drawn through the casing7 a valve in said tube, a stem connected to said Valve for adjusting the latter to vary the speed of rotation of the gyroscope, an indicator connected to said stein for movement therewithand a reference member adjacent said indicator for coopeiatingr therelwith to-show the extent ot adjustment of centralizing means therefor which is very' sensitive'when the gyroscope is near its normal position, but Whiclropposes precession about said axis with greater force when the gyroscope is further displaced from its central position and indicating means associated with said gyroscope for showing the rate of turn of the vehicle.

17. In a turn indicator for dirigible vehicles, a gyroscope mounted for precession about an axis at an angle to the vertieai, yielding means for opposing said precession means comprising av rotatable member 'for altering at will the resistance offered by said yieldinfi'neans to said precession, and a. rate of turn indicator associated with said gymscope.

1n testimony i whereof have anixed my slgnature. A

LAWRENGE B. SPERRY. 

